git.scottworley.com Git - tablify/blob - src/lib.rs

   1 use std::collections::{HashMap, HashSet};
   2 use std::io::BufRead;
   3 use std::iter::Iterator;
   4
   5 const HEADER: &str = "<!DOCTYPE html>
   6 <html>
   7 <head>
   8   <meta charset=\"utf-8\">
   9   <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">
  10   <style>
  11     /* h/t https://wabain.github.io/2019/10/13/css-rotated-table-header.html */
  12     th, td { white-space: nowrap; }
  13     th { text-align: left; font-weight: normal; }
  14     table { border-collapse: collapse }
  15     tr.key > th { height: 8em; vertical-align: bottom; line-height: 1 }
  16     tr.key > th > div { width: 1em; }
  17     tr.key > th > div > div { width: 5em; transform-origin: bottom left; transform: translateX(1em) rotate(-65deg) }
  18     td { border: thin solid gray; }
  19     td.numeric { text-align: right; }
  20     td.yes { border: thin solid gray; background-color: gray; }
  21     td.spacer { border: none; }
  22     /* h/t https://stackoverflow.com/questions/5687035/css-bolding-some-text-without-changing-its-containers-size/46452396#46452396 */
  23     .highlight { text-shadow: -0.06ex 0 black, 0.06ex 0 black; }
  24     img { height: 1.2em; }
  25   </style>
  26   <script>
  27     function highlight(id)       { const e = document.getElementById(id); if (e) { e.classList.add(   \"highlight\"); } }
  28     function clear_highlight(id) { const e = document.getElementById(id); if (e) { e.classList.remove(\"highlight\"); } }
  29     function h2(a, b)  {       highlight(a);       highlight(b); }
  30     function ch2(a, b) { clear_highlight(a); clear_highlight(b); }
  31   </script>
  32 </head>
  33 <body>
  34   <table>
  35     <tbody>";
  36 const FOOTER: &str = "    </tbody>
  37   </table>
  38 </body>
  39 </html>";
  40
  41 #[derive(Debug, PartialEq, Eq, Hash)]
  42 struct Entry(String);
  43
  44 #[derive(Debug, PartialEq, Eq)]
  45 struct RowInput {
  46     label: String,
  47     entries: Vec<Entry>,
  48 }
  49
  50 struct Reader<Input: Iterator<Item = Result<String, std::io::Error>>> {
  51     input: std::iter::Enumerate<Input>,
  52     row: Option<RowInput>,
  53 }
  54 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Reader<Input> {
  55     fn new(input: Input) -> Self {
  56         Self {
  57             input: input.enumerate(),
  58             row: None,
  59         }
  60     }
  61 }
  62 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Iterator for Reader<Input> {
  63     type Item = Result<RowInput, std::io::Error>;
  64     fn next(&mut self) -> Option<Self::Item> {
  65         loop {
  66             match self
  67                 .input
  68                 .next()
  69                 .map(|(n, r)| (n, r.map(|line| String::from(line.trim_end()))))
  70             {
  71                 None => return Ok(std::mem::take(&mut self.row)).transpose(),
  72                 Some((_, Err(e))) => return Some(Err(e)),
  73                 Some((_, Ok(line))) if line.is_empty() && self.row.is_some() => {
  74                     return Ok(std::mem::take(&mut self.row)).transpose()
  75                 }
  76                 Some((_, Ok(line))) if line.is_empty() => {}
  77                 Some((n, Ok(line))) if line.starts_with(' ') => match &mut self.row {
  78                     None => {
  79                         return Some(Err(std::io::Error::other(format!(
  80                             "{}: Entry with no header",
  81                             n + 1
  82                         ))))
  83                     }
  84                     Some(ref mut row) => row.entries.push(Entry(String::from(line.trim()))),
  85                 },
  86                 Some((_, Ok(line))) => {
  87                     let prev = std::mem::take(&mut self.row);
  88                     self.row = Some(RowInput {
  89                         label: line,
  90                         entries: vec![],
  91                     });
  92                     if prev.is_some() {
  93                         return Ok(prev).transpose();
  94                     }
  95                 }
  96             }
  97         }
  98     }
  99 }
 100
 101 fn read_rows(input: impl std::io::Read) -> impl Iterator<Item = Result<RowInput, std::io::Error>> {
 102     Reader::new(std::io::BufReader::new(input).lines())
 103 }
 104
 105 fn column_counts(rows: &[RowInput]) -> Vec<(usize, String)> {
 106     let mut counts: Vec<_> = rows
 107         .iter()
 108         .flat_map(|r| r.entries.iter().collect::<HashSet<_>>().into_iter())
 109         .fold(HashMap::new(), |mut cs, e| {
 110             cs.entry(String::from(&e.0))
 111                 .and_modify(|n| *n += 1)
 112                 .or_insert(1);
 113             cs
 114         })
 115         .into_iter()
 116         .map(|(col, n)| (n, col))
 117         .collect();
 118     counts.sort();
 119     counts
 120 }
 121
 122 /// # Errors
 123 ///
 124 /// Will return `Err` if
 125 ///   * there's an i/o error while reading `input`
 126 ///   * the log has invalid syntax:
 127 ///     * an indented line with no preceding non-indented line
 128 pub fn tablify(input: impl std::io::Read) -> Result<String, std::io::Error> {
 129     let rows = read_rows(input).collect::<Result<Vec<_>, _>>()?;
 130     let _columns = column_counts(&rows);
 131     Ok(String::from(HEADER) + "Hello, world!" + FOOTER)
 132 }
 133
 134 #[cfg(test)]
 135 mod tests {
 136     use super::*;
 137
 138     #[test]
 139     fn test_read_rows() {
 140         assert_eq!(
 141             read_rows(&b"foo"[..]).flatten().collect::<Vec<_>>(),
 142             vec![RowInput {
 143                 label: String::from("foo"),
 144                 entries: vec![]
 145             }]
 146         );
 147         assert_eq!(
 148             read_rows(&b"bar"[..]).flatten().collect::<Vec<_>>(),
 149             vec![RowInput {
 150                 label: String::from("bar"),
 151                 entries: vec![]
 152             }]
 153         );
 154         assert_eq!(
 155             read_rows(&b"foo\nbar\n"[..]).flatten().collect::<Vec<_>>(),
 156             vec![
 157                 RowInput {
 158                     label: String::from("foo"),
 159                     entries: vec![]
 160                 },
 161                 RowInput {
 162                     label: String::from("bar"),
 163                     entries: vec![]
 164                 }
 165             ]
 166         );
 167         assert_eq!(
 168             read_rows(&b"foo\n bar\n"[..]).flatten().collect::<Vec<_>>(),
 169             vec![RowInput {
 170                 label: String::from("foo"),
 171                 entries: vec![Entry(String::from("bar"))]
 172             }]
 173         );
 174         assert_eq!(
 175             read_rows(&b"foo\n bar\n baz\n"[..])
 176                 .flatten()
 177                 .collect::<Vec<_>>(),
 178             vec![RowInput {
 179                 label: String::from("foo"),
 180                 entries: vec![Entry(String::from("bar")), Entry(String::from("baz"))]
 181             }]
 182         );
 183         assert_eq!(
 184             read_rows(&b"foo\n\nbar\n"[..])
 185                 .flatten()
 186                 .collect::<Vec<_>>(),
 187             vec![
 188                 RowInput {
 189                     label: String::from("foo"),
 190                     entries: vec![]
 191                 },
 192                 RowInput {
 193                     label: String::from("bar"),
 194                     entries: vec![]
 195                 }
 196             ]
 197         );
 198         assert_eq!(
 199             read_rows(&b"foo\n \nbar\n"[..])
 200                 .flatten()
 201                 .collect::<Vec<_>>(),
 202             vec![
 203                 RowInput {
 204                     label: String::from("foo"),
 205                     entries: vec![]
 206                 },
 207                 RowInput {
 208                     label: String::from("bar"),
 209                     entries: vec![]
 210                 }
 211             ]
 212         );
 213         assert_eq!(
 214             read_rows(&b"foo  \n bar  \n"[..])
 215                 .flatten()
 216                 .collect::<Vec<_>>(),
 217             vec![RowInput {
 218                 label: String::from("foo"),
 219                 entries: vec![Entry(String::from("bar"))]
 220             }]
 221         );
 222
 223         let bad = read_rows(&b" foo"[..]).next().unwrap();
 224         assert!(bad.is_err());
 225         assert!(format!("{bad:?}").contains("1: Entry with no header"));
 226
 227         let bad2 = read_rows(&b"foo\n\n bar"[..]).nth(1).unwrap();
 228         assert!(bad2.is_err());
 229         assert!(format!("{bad2:?}").contains("3: Entry with no header"));
 230     }
 231
 232     #[test]
 233     fn test_column_counts() {
 234         assert_eq!(
 235             column_counts(
 236                 &read_rows(&b"foo\n bar\n baz\n"[..])
 237                     .collect::<Result<Vec<_>, _>>()
 238                     .unwrap()
 239             ),
 240             vec![(1, String::from("bar")), (1, String::from("baz"))]
 241         );
 242         assert_eq!(
 243             column_counts(
 244                 &read_rows(&b"foo\n bar\n baz\nquux\n baz"[..])
 245                     .collect::<Result<Vec<_>, _>>()
 246                     .unwrap()
 247             ),
 248             vec![(1, String::from("bar")), (2, String::from("baz"))]
 249         );
 250         assert_eq!(
 251             column_counts(
 252                 &read_rows(&b"foo\n bar\n bar\n baz\n bar\nquux\n baz"[..])
 253                     .collect::<Result<Vec<_>, _>>()
 254                     .unwrap()
 255             ),
 256             vec![(1, String::from("bar")), (2, String::from("baz"))]
 257         );
 258     }
 259 }